Although Von Miller plays professional football in Colorado, where marijuana is legal, he still has to play by the rules of the NFL.

Amendment 64, which was approved by Colorado voters in November 2012, is now enacted as Article 18, Section 16 of the state constitution. The amendment allows those 21 years of age or older to use and possess marijuana.

However, the amendment states: "Nothing in this section is intended ... to affect the ability of employers to have policies restricting the use of marijuana by employees."

In short, even though the law permits marijuana use, private businesses don't have to. Marijuana is one of the drugs banned by the NFL.

Miller is appealing a four-game suspension for an unspecified violation of the NFL drug policy. The Denver Post received documentation that showed Miller tested positive for marijuana multiple times during his 2011 rookie season.